首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   15569篇
  免费   997篇
  国内免费   97篇
耳鼻咽喉   133篇
儿科学   520篇
妇产科学   376篇
基础医学   2248篇
口腔科学   263篇
临床医学   1371篇
内科学   3862篇
皮肤病学   494篇
神经病学   1625篇
特种医学   318篇
外科学   1385篇
综合类   45篇
一般理论   8篇
预防医学   1319篇
眼科学   281篇
药学   1163篇
中国医学   40篇
肿瘤学   1212篇
  2024年   23篇
  2023年   202篇
  2022年   522篇
  2021年   890篇
  2020年   415篇
  2019年   638篇
  2018年   697篇
  2017年   431篇
  2016年   492篇
  2015年   577篇
  2014年   734篇
  2013年   956篇
  2012年   1315篇
  2011年   1318篇
  2010年   789篇
  2009年   611篇
  2008年   959篇
  2007年   936篇
  2006年   836篇
  2005年   757篇
  2004年   619篇
  2003年   559篇
  2002年   500篇
  2001年   80篇
  2000年   67篇
  1999年   81篇
  1998年   94篇
  1997年   82篇
  1996年   49篇
  1995年   37篇
  1994年   38篇
  1993年   29篇
  1992年   41篇
  1991年   25篇
  1990年   26篇
  1989年   16篇
  1988年   13篇
  1987年   16篇
  1986年   19篇
  1985年   19篇
  1984年   13篇
  1983年   21篇
  1982年   10篇
  1981年   7篇
  1980年   9篇
  1979年   8篇
  1977年   13篇
  1976年   7篇
  1974年   13篇
  1973年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Segmentation and registration tools are commonly used in radiotherapy for target and at risk organs localisation. In this work the performances of three different segmentation tools and of a surface matching registration technique, used on computed tomography (CT) and magnetic resonance (MR) images for the treatment planning of conformal prostate carcinoma, are studied. The accuracy of the segmentation and registration tools was evaluated by phantom experiment and on patient data, respectively. A preliminary estimate of MR image distortion was also performed.  相似文献   
2.
泪管-耳-牙-指(趾)(LADD)综合征是一种具有多种表现的常染色体显性遗传疾病。最初在1967年由Levy报道。1例双侧泪液系统缺失、杯状耳、干嘴,以及牙、手臂和指(趾)异常的单发病例。之后一些新发现的临床表现,如肾脏异常、唾液腺缺乏、先天性髋脱位、先天性裂孔疝和横膈疝、感觉性耳聋和传导性耳聋、牙发育不全、四肢异常、口腔干燥和眼干都被报道与此综合征有关。  相似文献   
3.
Successful efforts in improving breastfeeding initiation rates at an urban teaching hospital prompted the hospital to create a lactation consultant (LC) position in the outpatient setting to focus on breastfeeding duration. This article reviews the complexity of the clinic setting, with the challenges and benefits of the consultant's first year in one of the hospital's outpatient clinics. Preliminary data collected by the consultant suggest that patients counseled by the LC in the outpatient clinic setting have longer breastfeeding duration rates.  相似文献   
4.
To obtain a new model of chronic portal hypertension in the rat, two classical methods to produce portal hypertension, partial portal vein ligation and the oral administration of thioacetamide (TAA), have been combined. Male Wistar rats were divided into four groups: 1 (control; n?=?10), 2 [triple partial portal vein ligation (TPVL); n?=?9], 3 (TAA; n?=?11), and 4 (TPVL plus TAA; n?=?9). After 3 months, portal pressure, types of portosystemic collateral circulation, laboratory hepatic function tests (aspartate aminotransferase, alanine aminotransferase, bilirubin, alkaline phosphatase, and gamma-glutamyl transpeptidase) and liver histology were studied. The animals belonging to group 2 (TPVL) developed extrahepatic portosystemic collateral circulation, associated with mesenteric venous vasculopathy without hepatic destructurization or portal hypertension. Animals from group 3 (TAA) developed cirrhosis and portal hypertension but not extrahepatic portosystemic collateral circulation, or mesenteric venous vasculopathy. Finally, the animals from group 4 (TPVL?+?TAA) developed cirrhosis, portal hypertension, portosystemic collateral circulation, and mesenteric venous vasculopathy. The association of TPVL and TAA can be used to obtain a model of chronic portal hypertension in the rat that includes all the alterations that patients with hepatic cirrhosis usually have. This could, therefore, prove to be a useful tool to study the pathophysiological mechanisms involved in these alterations.  相似文献   
5.
6.
Hypoxia is related to poor prognosis because it is associated to chemo-and radioresistance. During recent years the evolution of imaging methods like PET/CT and MRI has meant the appearance of new perspectives with direct implications in radiation therapy. We discuss previous experiences in staging, planning and in the follow-up process with these techniques for measuring tumour hypoxia.  相似文献   
7.
8.
Marta Poore 《分娩》1986,13(2):127-127
  相似文献   
9.
Objective The purpose of this study is to analyze clinical aspects and disease-free survival (DFS) in children less than 3 years of age diagnosed with low-grade astrocytoma. Methods In a period of 24 years (1980–2004), a total of 43 (5.4%) children were registered with these characteristics. Twenty-three patients had pilocytic astrocytoma, 18 diffused, and 2 mixed. Thirty-one (72.1%) children had incomplete surgical tumor resection and 12 (27.9%) had a complete tumor resection. Twelve (27.9%) patients had cranial radiotherapy and 17 (39.5%) received chemotherapy. Overall survival was recorded in 23 (53%). DFS was 50% at 250 months of follow-up for the whole group. DFS for the supratentorial group was 60% at 250 months, whereas, for the infratentorial, it was 22% at 120 months (p = 0.008). Conclusion The only favorable prognostic pattern was the supratentorial presentation. Radiotherapy and chemotherapy did not alter the outcome.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号